Flat Panel X-ray Sources for Small Animal Cardiac CT Abstract Cardiovascular disease (CVD) is the leading cause of death in the United States and a major cause of disability. With the recent introduction of dual source CT scanners for human cardiac imaging, we are now able to obtain temporal resolution of 42 to 83 ms. This permits accurate assessment of global functional parameters as well as quantification of time-dependent variables and reliable evaluation of regional wall motion. In recent years, advances in genetic engineering have resulted in the development of a variety of mouse CVD models that have become powerful tools for pre-clinical studies of factors contributing to coronary disease. However, dedicated imaging systems with high spatial and temporal resolution are required to image the mouse heart due to its small size and fast heart rate. Here we propose to design a prototype small animal cardiac CT system in collaboration with the University of Virginia (UVa) based on novel flat panel digitally addressable x- ray source (DAXS). The DAXS uses an innovative architecture in which electrons from cold cathode arrays formed in pixel configurations on the source exit window generate x-ray flux at the target opposite. The x-rays pass through the low-attenuation cold cathode emitters and out of the exit window. The metal x-ray target is a broad and flat W/Cu plate which forms the outer wall of the vacuum envelope. The cold cathode arrays are fabricated using microlithographic techniques, and as many as 10,000 individual emitters can be fabricated on a 1 mm2 spot. The x-ray flux at each pixel can be modulated over a broad range by varying the potential across the cathode and gate electrodes. Each x-ray pixel (xel) can be individually addressed at high speeds, leading to reduced motion blurring due to cardiac motion. The ability to rapidly address xels and vary intensity will offer new flexibility in delivering precise amounts of x-ray flux to target locations. The system described here will lead to a new generation of compact, fast, affordable and transportable small animal cardiac CT systems. PUBLIC HEALTH RELEVANCE: Flat Panel X-ray Sources for Small Animal Cardiac CT Narrative Cardiovascular disease (CVD) is the number 1 killer in the United States. Imaging mouse models developed for preclinical studies of factors contributing to CVD requires special dedicated scanners. We propose the development of a small animal cardiac CT system based on novel digitally addressable x-ray source panels offering unique capabilities not available with current microfocus x-ray sources. Since the x-ray pixels can be addressed electronically in less than a microsecond cardiac-gated scans can be acquired that permit isolation of particular phases of the cardiac cycle for accurate assessment of global functional parameters as well as quantification of time-dependent variables and reliable evaluation of regional wall motion.